The long term goal of this project is to understand the mechanism(s) by which echoviruses cause disease in humans. Establishment of transgenic mice expressing human proteins that serve as echovirus receptors will provide a small animal model for echovirus infection. Transgenic mice generated in this proposal will be used to study sites of echovirus infection, routes of in vivo spread, determinants of tissue tropism and organ specific disease caused by echovirus infection. Data generated from these studies will be useful for the development of echovirus vaccines or antiviral drugs.